Aluminum alloy



Patented Oct. 6, 1936 UNITED STATES PATENT OFFICE anunnwm armor H many, a corporation of Germany No Drawing. Application July 9, 1935, Serial No.

'* 30,566. In Germany July 19, 1934 2 Claims. ((71. 75-138) Object of my present invention is a process for increasing the resistance against corrosion aluminum and aluminum alloys.

Since a; great number or years the particular 5 industries have made great eilorts to produce alloys especially for the purpose of armament and aeroplane construction which are resistant against the attack of air, moisture, atmosphere and sea water and their combined action.

There exist already a great number oi alloys which show a decided improvement in the desired direction. But the resistance of these alloys against corrosion is not high enough whilst,

- also, the properties of the known alloys as regards mechanical strength and other technological properties were not at all satisfactory sothat the respective industry was compelled to reduce its requirements in this direction as long as the corrosion resistance was increased.

I have found that aluminum-thorium-alloys show, when subjected to corrosion trials, results which appear far superior .to the best alloys vhitherto known.

Objects oi! my invention are aluminum alloys which are especially suitable for the use or such construction parts which are exposed to the influence of the atmosphere and to water such as is round in nature for instance sea water, especially in conjunction with air. Alloys ac- 30 cording to my invention contain small amounts of thorium. The amounts which are required in order to improve the resistance of the aluminum "or the alloys respectively agalnst corrosion may vary from .1 to 6 percent. I have found that alloys are particularly advantageous which have a thorium content of about .8 to 2.5 percent.

In addition to thorium the alloys may, accord- 5 'ing to my invention, contain other components which increase the resistance of the aluminum or influence its other properties in a favorable sense. Such components are for instance me-. tallic sodium, manganese, magnesium, copper, 10 zinc, silicium, nickel or the like which may be alloyed with the aluminum-thorium composition either singly or in combination of two or more metals.

Alloys of aluminum of the most varied kind 15 containing, in addition, thorium according to my invention, have proved especially valuable for the construction of aeroplanes, sea planes and the like devices, further for naval construction, above all for those parts which are above the go water-line, since by the addition of thorium the alloys according to my invention possess an excellent resistance against the atmosphere, moisture and, especially, sea-water, or their combined action.

What I claim is:

l. A corrosion resisting alloy consisting of an alloy containing .1 to.6% of thorium and the remainder aluminum.

2. A corrosion resisting alloy consisting of an so alloy containing .8 to 2.5% of thorium and the remainder aluminum.

WILHAM GGERTLER. 

